Printed circuit boards (hereinafter boards) are the basic building blocks of any type of electronic product. Further, as can be noted with virtually any electronic product, these products and the boards utilized therein, continually have been decreased in size without loss of any functions or with additional functions added thereto. For example, in mobile applications, such as vehicle two way communication radios, the standard radio size has been 3 by 18 by 24 inches. These radios typically were accommodated in the dash, in the body, in the trunk, under the seat or in the floor board of the vehicles. The design criterion for newer radios, now is on the order of 21/2 by 7 by 12 inches, which allows installation under the dash of modern automobiles.
Along with the reduction in size has come the need and desire to utilize boards, which are nonplanar in shape and also to mount the boards to components during assembly. The boards desirably would be mounted before the circuits are applied thereto, to avoid stresses or other possible circuit defects in mounting the boards with the circuits already formed thereon. Further, it can be desirable to form the circuit right on a portion of the assembled product without mounting a separate board for the circuit.
Current techniques for applying solder paste patterns and electronic components are based on utilizing planar boards, which can be mounted on frames in the solder paste dispensing machines, such as screen printing machines. These machines are not easily adaptable to utilizing boards which are not planar, and cannot apply solder paste patterns to any type of assembled products. Further, these machines use a so-called puddle and squeegee technique for applying the solder paste to the boards. A puddle of solder paste is squeegeed across the boards which are individual planar defined units, so that the excess solder paste flowing off the sides and end of the boards does not cause a problem.
It is therefore a general object of the present invention to provide a method and apparatus for dispensing solder paste in a controlled manner onto planar boards.
It is a further object of the present invention to provide a method and apparatus for dispensing solder paste in a controlled manner onto non-planar boards.
It also is an object of the present invention to provide a method and apparatus for applying solder paste to boards mounted on an assembled or partially assembled product.
It is a still further object of the present invention to provide a method and apparatus for applying solder paste directly to a portion of a component of an assembled or partially assembled product.